1. Field of the Invention
The present invention relates to an X-ray generator emitting characteristic X-rays and an X-ray photographing apparatus including the X-ray generator.
2. Description of the Related Art
X-rays are used to perform non-destructive inspection, structural and physical property inspection of a material, image diagnosis, and security searching in the fields of industry, science, and medical treatment. In general, a photographing apparatus using X-rays includes an X-ray generator emitting the X-rays, and a detecting unit for detecting the X-rays that pass through an object.
Here, the X-ray generator generates the X-rays by generally generating electron beams emitted from an anode and colliding such electron beams with a cathode. The X-rays may be composed of Bremsstrahlung X-rays that are emitted mainly by deceleration of the electron beams, and characteristic X-rays emitted from an energy level of a target material.
The Bremsstrahlung X-rays represent a wide range spectrum, and thus may be referred to as polychromatic X-rays. Therefore, when the Bremsstrahlung X-rays are used, an X-ray image is produced, in which absorption coefficients of the material are mixed, and thus, contrast characteristics of the polychromatic X-ray image are degraded when the polychromatic X-ray image is compared with an image produced when the characteristic X-rays, which are monochromatic X-rays, are used. Thus, it is difficult to distinguish materials from each other in the target when using polychromatic X-ray imaging.
In addition, when the Bremsstrahlung X-rays are projected onto a human body, they are mostly absorbed by the human body, thus increasing the amount of radiation exposure to the human body. Therefore, a filter formed of aluminum or copper is generally disposed to remove the X-rays of a low level energy region and thus to prevent exposure of the human body to such low level energy X-rays, when imaging diagnosis is performed.
Therefore, research regarding the use of characteristic X-rays to obtain a high quality X-ray image or to perform the imaging diagnosis is being conducted, since there is a need to obtain such high quality X-ray images while minimizing exposure of a target, such as the human body, to the X-rays.